The mission of this Program is to prepare a cadre of outstanding epidemiologists in the areas of reproductive, obstetric, perinatal and pediatric epidemiology through rigorous academic training in research methodology and the epidemiology and biology of reproductive, obstetric, perinatal and pediatric health, and through mentored research. A distinguished faculty provides a variety of substantial opportunities for research experience. The interest in these areas has constantly risen over the past decade or two among our graduate student population and applicants for graduate studies at Harvard School of Public Health. Doctoral Candidates in Epidemiology includes pre- doctoral candidates either with or without a prior doctoral degree who undertake 2-3 years of coursework, in addition to 2-3 years of research, in the course of earning a doctoral degree in Epidemiology. We request 2 new trainee positions per year and funding is requested for four years of study (8 prevalent training slots). The Program is based in the Department of Epidemiology of the Harvard School of Public Health. The faculty at the Harvard School of Public Health and the Harvard teaching hospitals combine a extraordinary wealth of expertise and experience in these areas and provide diverse research projects in the developed and developing world and including gynecologic conditions, adverse pregnancy outcomes, gynecologic tumors, pharmacoepidemiology during pregnancy, epigenetics in the context of developmental origins of health and disease in which students can participate. This proposal continues a long history of excellence in training in epidemiology at Harvard University.